By Jhoo Dong-chanThe nation's eating-out expense index has reached a record high after 23 months due to the minimum wage hike. The consumer price index still maintained at a low level with a 1 percent increase from a year ago, but this year's minimum wage hike of 16.4 percent is causing concern that it may cause a domino effect in the low-income bracket's spending.According to Statistics Korea, the country's restaurant price index grew 3.2 percent from a year ago in January. Lunch box prices were also up 2.3 percent.The findings also suggested restaurant food prices for the low- and medium-income brackets, including instant noodles and kimbab, all increased last month.Because of an increase in restaurant food prices, last month's eating-out expenses marked 2.8 percent, the highest level since it reached 2.9 percent in February 2016.Last month's eating-out expenses also top the annual average figure for the last five years.The annual eating-out expenses index recorded 2.4 percent in 2017, 2.5 percent in 2016, 2.3 percent in 2015, 1.4 percent in 2014 and 1.5 percent in 2013."We had no choice but to increase our food prices because of the minimum wage hike," a Seoul restaurant owner surnamed Kwak said."Not only labor costs but also the prices of vegetables are other reasons behind the food price hike."The government said that the minimum wage hike was not as big a burden as food material costs."They are just looking for a reason to increase their food prices. One increases (their prices) and others jump on the bandwagon," a government official was quoted as saying.Small-size business owners immediately rebutted the government's claim."My store runs in three shifts. I used to hire for two shifts. Now, my wife and I are running it in the morning and afternoon shifts. We've decided to hire just one part-time worker only for the night shift starting this year," a convenience store owner surnamed Paik said."We can't afford to hire two part-timers anymore. There is no point running a convenience store if we consider this year's minimum wage. I heard a number of other convenience store owners have decided not to open their stores at night. I believe the wage hike is hurting not only business owners like us but also jobseekers."According to Albamon, the nation's largest part-timer recruiting website, the total number of job openings has declined for the first time in five years. It also conducted a survey of 1,458 employees and jobseekers over their job security, and 72 percent of them said they were worried about possible layoffs while experiencing difficulty finding a job.Honoring his presidential election pledge to raise the minimum wage to 10,000 won ($9.35) by 2020, President Moon Jae-in has exercised his influence with the Minimum Wage Commission since taking office last year. Last July, the commission set the 2018 minimum wage at 7,530 won per hour, up 16.4 percent from last year's 6,470 won. It was the largest hike in history.